In view of Lemma 8.1 in [1]}, there exists \( \mathcal {P}\in \mathrm {SL}(2,{\mathbb {R}}) \)  with \( |\mathcal {P}|\le 2(\frac{|b_0-\delta _1 b_1|}{\sqrt{d(\delta _1)}})^{\frac{1}{2}} \) , such that
\( \mathcal {P}^{-1}e^{b_0-\delta _1 b_1}\mathcal {P}=R_{\sqrt{d(\delta _1)}}. \) 
